They were caught on video earlier this month yelling for help and saying "we've been tortured" from a prison van on their way to court.

US and Pakistani authorities have denied the accusations of mistreatment, which the suspects repeated on Tuesday saying authorities were trying to force them back to the US on "phoney charges".

'Lack of evidence'

On Tuesday Pakistani defence lawyers sought bail for the five saying the prosecution lacked evidence.

The pink-coloured tissue paper was dropped from a van bringing the five to court
"The allegations against them are vague. There is no substantial evidence available to show their guilt," Mohammad Shahid Kamal Khan, one of the defence lawyers, told reporters outside the court.

"It is a violation of the legal and fundamental rights to keep them in confinement."

Two of the five suspects are of Pakistani origin, one of Egyptian, one of Yemeni and one of Eritrean origin, and live in the US state of Virginia.

They were arrested days after arriving in Pakistan and have not been formally charged, but could face life imprisonment if they are tried and convicted.

Nadeem Akram Cheema, the public prosecutor, argued that a presidential decree stated that any suspect facing charges which carry more than 10 years in prison should not be granted bail.

"There are very limited chances for the bail of the accused," he told AFP, adding that the five would likely be formally charged at the next hearing on March 2.

The five told the court earlier they only wanted to provide fellow Muslims in Afghanistan with medical and financial help.